Guto Bebb MP, said Global Restructuring Group (GRG), the wing of RBS which handles loans classed as risky, sees distressed firms as "opportunities" to make money.
Many companies were told they suddenly had to pay large sums of money for their banking facilities or be forced to accept expensive reviews of their businesses, he said.
There are cases of "systematic bad behaviour" by GRG, he said, adding there is an "impression of a conflict of interest" by the decision to appoint legal firm Clifford Chance, which previously worked for RBS, to do an internal review.
A debate was called after a report by businessman Lawrence Tomlinson, which alleged that RBS deliberately forced companies into default to seize their properties.
Leading the debate, Mr Bebb said that in an interview with finance data firm Debtwire in October last year, the head of GRG, Derek Sach, said he sees struggling businesses as opportunities.
Mr Bebb said: "The vultures are hovering within GRG waiting for a supply of distressed businesses to be taken advantage of."
Financial Secretary ti the Treasury Sajid Javid said "We take the allegations that are made in that report very seriously.
"We are pleased the FCA has acted quickly so far to look at those very serious allegations."